This invention is an improvement upon sentinel node localization systems. One of the latest developments in the staging of breast cancer is the sentinel lymph node biopsy. The status of the regional lymph nodes in the axilla (armpit) are one of the most powerful predictors of the survival of women with invasive breast cancer. The current standard of care for women with invasive breast cancer is the surgical removal of approximately two-thirds of the axillary lymph nodes for tumor staging. Most breast cancer patients, fortunately, have no spread of cancer to the lymph nodes. However, they endure the morbidity of the axillary lymph node dissection. Complications of an axillary lymph node dissection include arm edema (swelling), numbness and pain in the arm and axilla, and increased costs due to longer hospitalization.
The concept of the sentinel lymph node biopsy is to sample the first draining lymph node (the "sentinel node") nearest the site of the patient's breast cancer. If there is no evidence of tumor spread, then the patient does not have to undergo an axillary lymph node dissection. The procedure involves injecting radioactive material around the site of the cancerous tumor in the breast. This procedure typically is done in a radiology/nuclear medical department followed by transportation of the patient to an operating room where a surgeon uses a hand held gamma probe (camera) to localize the area of greatest radioactivity in the draining lymph nodes. The surgeon will also inject blue dye around the cancerous site and perform a lymphangiogram to aid in the identification of the sentinel lymph node.
If the patient has a palpable breast cancer, then the radioactive material and blue dye can be injected by palpation. If, however, the cancerous tumor in the breast cannot be felt, a localization wire must be placed prior to the injection of radioactive material. This procedure entails placing a needle into the tumor while the breast is in compression (similar to a mammogram), and deploying a localization wire with a distal hook (to secure it into the breast) through the needle and into the breast.
For a routine surgical biopsy/lumpectomy, the needle is slowly withdrawn out of the breast leaving the localization wire in place localizing the breast cancer site. However, in order to inject the radioactive material and blue dye for the sentinel lymph node procedure, the needle must stay in place and not be removed. A disadvantage of leaving the needle in place is that the breast cannot be massaged following placement of the radioactive material and blue dye to enhance the uptake of injected material into the breast lymphatics. It also places the breast at greater risk of injury while the patient is being transported, for example, from a radiology department to an operating room. There is therefore a need for an improved procedure that will eliminate these disadvantages of the presently employed sentinel lymph node procedure.